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In the food context, people are always looking for alternative ways to substitute highly caloric sugars with sweeteners that have little or no calories. This is an ongoing effort to find new methods for creating sweet-tasting food without the negative health effects that come with consuming too much sugar. This study tested the capacity of 32 yeast strains to produce erythritol, mannitol, and arabitol in a medium containing glycerol or glucose as carbon sources. Two strains of Yarrowia lipolytica CCMA 0242 and CCMA 0357 and Candida rugosa CCMA 0371 were found to have the greatest capacity to produce erythritol, with yields of 5.19 ± 0.58, 4.60 ± 0.63 and 10.70 ± 0.01 g/L, respectively. The potential of the strains evaluated is promising, especially for C. rugosa , a yeast not yet explored for the production of polyols, which produced the highest amounts of erythritol, mannitol, and arabitol, using glycerol as a carbon source, contributing to a fermentative process economically competitive and with a great biotechnological application at the industrial level.

Ethanol is an important risk factor for the occurrence of several brain disorders that depend on the amount, period and frequency of its consumption. Chronic use of ethanol often leads to the development of neurodegenerative syndromes, which cause morphological and functional impairments such as foetal alcohol syndrome in newborns exposed to ethanol during pregnancy, Wernicke–Korsakoff Syndrome and, more rarely, Marchiafava–Bignami disease (MBD). MBD is characterized by primary degeneration of the corpus callosum, without inflammation and is associated with oxidative stress and hypovitaminosis, as well as altered mental status, to mention dementia, seizures, depression and so on. This review discusses MBD and poor nutrition as a risk factor for the development of such alcoholic syndrome, with focus on diagnosis, pathogenic aspects, signs and symptoms, as well as therapeutic perspectives. On the basis of the inclusion/exclusion criteria adopted, the performed search in scientific databases (Pubmed, Scielo and Google Scholar) resulted in 100 studies that are being presented and discussed in the present work. Review, case–control and cohort studies on alcoholism-associated hypovitaminosis, oxidative stress, MBD and ethanol metabolism pathways were admitted as relevant. We highlight that MBD is a poorly described, diagnosed, insidious and progressive condition, for which evidence suggests a synergism between ethanol-induced neurotoxic effects and hypovitaminosis B. Present treatment consists of vitamin B1(thiamine) supplementation. Nonetheless, other strategies such as the inclusion of antidepressants or steroidal anti-inflammatories as add-on therapies have been employed as an attempt to improve the damage. Indeed, both the diagnosis and treatment are difficult, and death occurs within few years.

We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy.

A bstract NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0 νββ ) decay of 136 Xe. The detector possesses two features of great value for 0 νββ searches: energy resolution better than 1% FWHM at the Q value of 136 Xe and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 × 10 −4 counts keV −1 kg −1 yr −1 . Accordingly, the detector will reach a sensitivity to the 0 νββ -decay half-life of 2.8 × 10 25 years (90% CL) for an exposure of 100 kg·year, or 6.0 × 10 25 years after a run of 3 effective years.

A bstract The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0 νββ ) decay of 136 Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0 νββ decay better than 10 27 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.

We propose to measure several transition frequencies between the 2S and the 2P states (Lamb shift) in muonic helium ions (μ4He +  and μ3He + ) by means of laser spectroscopy, in order to determine the alpha-particle and helion root-mean-square (rms) charge radius. In addition, the fine and hyperfine structure components will be revealed, and the magnetic moment distribution radius will be determined. The contribution of the finite size effect to the Lamb shift (2S − 2P energy difference) in μHe +  is as high as 20 %. Therefore a measurement of the transition frequencies with a moderate (for laser spectroscopy) precision of 50 ppm (corresponding to 1/20 of the linewidth) will lead to a determination of the nuclear rms charge radii with a relative accuracy of 3 ×10 − 4 (equivalent to 0.0005 fm). The limiting factor for the extraction of the radii from the Lamb shift measurements is given by the uncertainty of the nuclear polarizability contribution. Combined with an ongoing experiment at MPQ aiming to measure the 1S − 2S transition frequency in the helium ion, the Lamb shift measurement in μHe +  will lead to a sensitive test of problematic and challenging bound-state QED terms. This measurement will also help to clarify the discrepancy found in our previous μp experiment. Additionally, a precise knowledge of the absolute nuclear radii of the He isotopes and the hyperfine splitting of μ3He +  provide a relevant test of few-nucleon theories.

The room-temperature response of large-area avalanche photodiodes (LAAPDs) to 128- and 172-nm light pulses is investigated. The minimum detectable number of photons, which can produce a signal just above the noise level, is found to be around 1300 and 600 photons, respectively. The LAAPD relative statistical fluctuations in the detection of 15 000 photons of 128 nm and 25 500 photons of 172 nm were found to be about 3.9% and 2.2%, respectively. Both the minimum detectable number of photons and statistical fluctuations do not depend on the photon wavelength, but rather on the number of charge carriers produced by the light pulse in the LAAPD. For these light levels, good LAAPD performance is already achieved for gains as low as 30 to 60.

A bstract Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in 136 Xe. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a 228 Th calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses.

A bstract Double electron capture by proton-rich nuclei is a second-order nuclear process analogous to double beta decay. Despite their similarities, the decay signature is quite different, potentially providing a new channel to measure the hypothesized neutrinoless mode of these decays. The Standard-Model-allowed two-neutrino double electron capture (2 νEC EC ) has been predicted for a number of isotopes, but only observed in 78 Kr, 130 Ba and, recently, 124 Xe. The sensitivity to this decay establishes a benchmark for the ultimate experimental goal, namely the potential to discover also the lepton-number-violating neutrinoless version of this process, 0 νEC EC . Here we report on the current sensitivity of the NEXT-White detector to 124 Xe 2 νEC EC and on the extrapolation to NEXT-100. Using simulated data for the 2 νEC EC signal and real data from NEXT-White operated with 124 Xe-depleted gas as background, we define an optimal event selection that maximizes the NEXT-White sensitivity. We estimate that, for NEXT-100 operated with xenon gas isotopically enriched with 1 kg of 124 Xe and for a 5-year run, a sensitivity to the 2 νEC EC half-life of 6 × 10 22 y (at 90% confidence level) or better can be reached.

The charge radius of the proton, the simplest nucleus, is known from electron-scattering experiments only with a surprisingly low precision of about 2%. The poor knowledge of the proton charge radius restricts tests of bound-state quantum electrodynamics (QED) to the precision level of about 6 × 10 –6 , although the experimental data themselves (1S Lamb shift in hydrogen) have reached a precision of 2 × 10 –6 . The determination of the proton charge radius with an accuracy of 10 –3 is the main goal of our experiment, opening a way to check bound-state QED predictions to a level of 10 –7 . The principle is to measure the 2S–2P energy difference in muonic hydrogen (µ – p) by infrared laser spectroscopy. The first data were taken in the second half of 2003. Muons from our unique very-low-energy muon beam are stopped at a rate of ~100 s –1 in 0.6 mbar H 2 gas where the lifetime of the formed µp(2S) atoms is about 1.3 µs. An incoming muon triggers a pulsed multistage laser system that delivers ~0.2 mJ at λ ≈ 6 µm. Following the laser excitation µp(2S) → µp(2P) we observe the 1.9 keV X-rays from 2P–1S transitions using large area avalanche photodiodes. The resonance frequency, and, hence, the Lamb shift and the proton radius, is determined by measuring the intensity of these X-rays as a function of the laser wavelength. A broad range of laser frequencies was scanned in 2003 and the analysis is currently under way. PACS Nos.: 36.10.Dr, 14.20.Dh, 42.62.Fi